'Slaughter' in the Bible

So the Philistines fought. Israel was defeated; they all ran home. The slaughter was very great; thirty thousand foot soldiers fell in battle.

Certainly if the army had eaten some of the enemies' provisions that they came across today, would not the slaughter of the Philistines have been even greater?"

Then Saul said, "Scatter out among the army and say to them, 'Each of you bring to me your ox and sheep and slaughter them in this spot and eat. But don't sin against the Lord by eating the blood." So that night each one brought his ox and slaughtered it there.

However, Saul and the army spared Agag, along with the best of the flock, the cattle, the fatlings, and the lambs, as well as everything else that was of value. They were not willing to slaughter them. But they did slaughter everything that was despised and worthless.